Because of better meeting communication requirements of people, wearable devices become increasing popular with people, and a smart watch is a most commonly used wearable device. Currently, all large communications equipment providers issue their respective smart watches, and competition in this field is intense.
Compared with a common watch, a smart watch is integrated with a communication function, and requires a built-in antenna to transmit or receive an electromagnetic signal. Currently, an antenna form such as a monopole or an IFA is generally used, and an antenna is arranged around a printed circuit board (Printed Circuit Board, PCB). To keep good transmit efficiency, an antenna requires headroom, and an arranged antenna has a height relative to the PCB.
However, headroom required by an antenna increases a size of a wearable device (such as a smart watch), and is not conducive to miniaturization of the wearable device. In addition, when an antenna such as a monopole or an IFA approaches a human body, electromagnetic waves transmitted by the antenna are mostly absorbed by the human body, which greatly deteriorates performance of the antenna and is harmful to health of the human body.